Giant Oarfish Dissected! Worms, Eggs Found Inside

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Researchers have dissected the two deep-sea oarfish that washed
ashore in southern California this month. So far, they found that
one was teeming with worms and the other was about to have
babies.

On Oct. 13, an 18-foot-long (5.5 meters)
oarfish was dragged to shore by a snorkeler at Catalina
Island. Because the species lives in deep, dark waters, up to
3,000 feet (915 meters) below the surface, intact specimens are
rarely discovered. Strangely enough, another smaller oarfish
washed ashore north of San Diego just a few days later.

Parasitologists from the University of California, Santa Barbara
jumped on the once-in-a-lifetime opportunity to study the elusive
creature and asked for a small tissue sample of the
oarfish that washed up at Catalina Island. When the
researchers cut through a tiny portion of the fish's intestine
last week, they found it was carrying a heavy parasite load.
[ Photos
of the Largest Fish on Earth ]

"Our findings say that these are actually majorly parasitized
fish," Armand Kuris, a professor of zoology at UC Santa Barbara,
said in a statement. "In this little piece of intestine that we
had, we found quite a few of these rather large larval tapeworms.
One of them was about 15 centimeters (6 inches) long."

Kuris and colleagues say they also found other parasites that
provide insight about the diet of the serpentlike fish. Embedded
in the intestine was the hooked proboscis of an adult
spiny-headed worm. Parasites hop from host to host throughout
their life cycle, so the fact that this worm was mature suggests
the oarfish ate its former host, likely krill or some deep-water
crustacean, the researchers said.

The second oarfish, which measured 14 feet (4 m) long, is also
under scientific scrutiny. Last week, researchers the Scripps
Institution of Oceanography reported that they found hundreds of
thousands of eggs inside the beast's 6-foot-long (1.8 m) ovaries,
according to the Associated
Press.

While the causes of death for both of the oarfish remain
mysteries, researchers have some working hypotheses.

Scientists with the U.S. National Oceanic and
Atmospheric Administration's Southwest Fisheries Science
Center performed a necropsy (an animal version of an autopsy) on
the smaller oarfish that washed up north of San Diego. Russ
Vetter, a NOAA biologist, said in a podcast from the agency that
the fish was quite fresh and seems to have stranded shortly
before it died.

Vetter suspects the creatures may have been carried closer to
shore by a strong ocean current, which the oarfish, being poor
swimmers, could not escape. Though they resemble the fearsome sea
serpents of folklore, a recent
video of a live oarfish in the Gulf of
Mexico revealed that the fish are actually quite motionless
in their natural habitat; they use paddlelike fins that help them
balance as their snakelike bodies hover vertically in the water.

Growing more than 30 feet (9 m) long, oarfish are the world's
longest bony fish, a group that includes almost all fish except
sharks and rays. (Whale sharks are the largest of all fish.)
Further examination of the preserved tissue samples of the
beached fish could help scientists uncover more secrets about the
species.

"With careful chemical analysis of the lipids and the proteins,
we should be able to tell what its diet is and where it fits in
the food chain," Vetter said in the podcast, adding that DNA will
allow scientists to examine how the oarfish evolved and how the
fish is related to other species.